Effects of harvest maturity on the quality of different parts of red-fleshed dragon fruit (Hylocereus polyrhizus)

This study evaluates variations in the proportions, nutritional composition, and bioactive compounds of the peel, pulp, and seeds of red-fleshed dragon fruit harvested at 28, 30, and 32 days after flowering. The results indicate that the proportion of peel and the moisture contents of both peel and pulp decrease with increasing harvest maturity, whereas reducing sugar, vitamin C, and betacyanin contents increase. The pulp accounts for the largest proportion of the fruit and contains high levels of reducing sugars, vitamin C, and betacyanin. The peel has the highest total phenolic content and total flavonoid content in the fruit. Dragon fruit seeds are rich in protein and fat and exhibit the highest antioxidant activity. Total phenolic content, total flavonoid content, and 2,2-diphenyl-1-picrylhydrazyl free-radical-scavenging activity increase with harvest maturity. Red-fleshed dragon fruit harvested between 30 and 32 days after flowering has high nutritional value and antioxidant activity.